Year	Percent
1996-01-01	23.9479
1997-01-01	24.0988
1998-01-01	18.9556
1999-01-01	19.9398
2000-01-01	21.2081
2001-01-01	20.0202
2002-01-01	23.1721
2003-01-01	19.6981
2004-01-01	19.1851
2005-01-01	17.4203
2006-01-01	18.1377
2007-01-01	17.6855
2008-01-01	17.2027
2009-01-01	19.6600
2010-01-01	17.9934
2011-01-01	20.7203
2012-01-01	19.9045
2013-01-01	19.0054
2014-01-01	17.8819
2015-01-01	17.1141
2016-01-01	18.7429